The aims of these studies are: to analyze determinants of clinical decision making in a number of problems in endocrinology and obstetrics/gynecology, to relate these findings to general psychological principles of human judgment and decision making, and to develop guidelines for improved decision making by analysis and modeling of the decision task and clinical judgments in the task. A variety of research strategies are employed including chart review with multivariate analysis, case vignettes to obtain physician responses to standardized materials, and retrospective reviews of decisions in an interview format. Two studies are currently in progress. The first is a review of the records of 124 obese patients referred to endocrinologists and a random sample of over 300 obese patients from an ambulatory care center. The aims of this study are to determine rates and reasons for referral of obese patients to specialists in endocrinology. The data will be analyzed to identify variables in the history and physical examination associated with the clinical judgment of obesity and with the decision to refer for specialized consultation. The second study examines the causes of variation in the laboratory workup of a single clinical problem by one expert endocrinologist. The patient chart is the basis of a retrospective review of 31 cases of hirsutism, done in an interview format as the physician thinks aloud about the case and responds to the questions of the interviewer/ethnographer about the decision made. Two additional studies are now being planned. The first utilizes a series of case vignettes of obese patients to study similarities and differences among physicians in clinical decision making while holding case mix constant. The vignettes are now being written and the sampling of physicians is under discussion. The second new study moves into the second research area of the program project, obstetrics/gyneology. We are planning a study of decisions around timing childbirth in cases of pregnancy-induced hypertension (toxemia). The decision involves balancing risks of prematurity against risks of continued exposure of the fetus to a hostile uterine environment.